1. Field of Endeavor
The present invention relates to tissue recognition and more particularly to a probe system for tissue recognition.
2. State of Technology
A New Release dated Jan. 10, 2001 by the Lawrence Livermore National Laboratory operated by the University of California provides the following information, xe2x80x9cThe pain and anxiety women experience undergoing breast cancer tests and awaiting the results may soon be lessened thanks to a new, minimally invasive diagnostic tool that can instantly detect cancerous tissue. Lawrence Livermore National Laboratory has partnered with San Jose-based BioLuminate, Inc. to develop xe2x80x9cSmart Probe,xe2x80x9d a tool for earlier, more accurate breast cancer detection that removes no tissue and is expected to achieve accuracy levels comparable to surgical biopsies in detecting cancerous cells.
The BioLuminate xe2x80x9cSmart Probe,xe2x80x9d smaller than the needle used in routine blood tests, is inserted into breast tissue after an initial screening indicates an area of concern. The probe looks for multiple known indicators of breast cancer, instantaneously providing physicians with information they can use to determine whether more invasive and costly tests are necessary. The results of the xe2x80x9cSmart Probexe2x80x9d procedure are immediately available to patients, helping relieve anxiety. First human studies using the device are expected to begin this spring at sites to be selected in Northern California. xe2x80x9cPhysicians have been seeking a way to acquire more specific information about a suspected cancer site before performing a biopsy or surgery,xe2x80x9d said Neil Gorrin, MD, Assistant Chief of Surgery at Kaiser Permanente Medical Center in South San Francisco. xe2x80x9cThe xe2x80x9cSmart Probexe2x80x9d not only is less invasive, but it provides several specific measurements of known cancer indicators in real time, which will improve our chances of making the right diagnosis and treatment plan for the patient.xe2x80x9d
Fewer Unnecessary Biopsiesxe2x80x94Breast cancer is the second leading cause of death among women in the United States. Last year in the U.S., 182,800 women were diagnosed with breast cancer and more than 40,800 died of the disease. In the U.S. each week, approximately 16,000 women undergo unnecessary, surgical breast biopsies on suspicious tissue that turns out benign. In addition, physicians miss about 4,600 cases of breast cancer each week during physical examinations and mammogram reviews. xe2x80x9cBy using the BioLuminate xe2x80x98Smart Probexe2x80x99 before biopsies are performed on suspicious lesions, many unnecessary surgeries can be eliminated,xe2x80x9d said Richard Hular, President and CEO of BioLuminate. xe2x80x9cNot only is this a great benefit for the patient, it also has the potential to save the U.S. healthcare system over $2 billion annually.xe2x80x9d
Cancer Indicators Measured in Real Timexe2x80x94Once a mammogram or physical exam has detected a possible malignant lump, xe2x80x9cSmart Probexe2x80x9d is inserted into the tissue and guided to the suspicious region. Sensors on the tip of the probe measure optical, electrical and chemical properties that are known to differ between healthy and cancerous tissues. The xe2x80x9cSmart Probexe2x80x9d can detect multiple (5 to 7) known indicators of breast cancer. Tissue measurements are made in real time in both normal and suspect tissue. xe2x80x9cSmart Probe""sxe2x80x9d sensors begin gathering information the moment the probe is inserted into tissue. Computer software compares the real-time measurements to a set of known, archived parameters that indicate the presence or absence of cancer. The results are displayed instantly on a computer screen. xe2x80x9cThe key technology and experience that Lawrence Livermore Lab has to offer will allow the xe2x80x98Smart Probexe2x80x99 to be much smaller than first conceived, and acquire data more accurately,xe2x80x9d said Luiz Da Silva, Ph.D, Livermore""s Associate Medical Technology Program Leader and primary investigator for the xe2x80x9cSmart Probe.xe2x80x9d xe2x80x9cIn addition, we will have the capacity to add additional measurements if necessary.xe2x80x9d
U.S. Pat. No. 5,303,026 for apparatus and method for spectroscopic analysis of scattering media by Karlheinz Strobl, Irving J. Bigio, and Thomas R. Loree, patented Apr. 12, 1994 provides the following background information, xe2x80x9cAttempts at in situ real-time diagnostics for complex biological media, have been only marginally successful because of limitations in the spectroscopic techniques that are applicable. Conventional fluorescence spectroscopy is generally unable to resolve differences among similar biological tissue samples (or subtle differences in a given tissue sample) and has generally not proven reliable in detecting malignancy except with the aid of drugs such as hematoporphyrin derivatives which are used as targeting fluorescers.xe2x80x9d
U.S. Pat. No. 5,349,954 for a tumor tissue characterization apparatus and method by Jerome J. Tiemann and Fay A. Marks, patented Sep. 27, 1994 provides the following background information, xe2x80x9cIn a conventional procedure, a radiologist performs x-ray mammography. If an abnormal breast process recorded on the resulting mammograms is considered suspicious, a surgical biopsy can be ordered. Immediately prior to the biopsy, the radiologist takes several more views or projections of the breast during preoperative localization of the abnormality and marks the location of the suspicious abnormality by impaling the region with a thin, hooked guide wire. The patient is then taken to an operating room and a surgeon performing the biopsy follows the hooked wire guide to the precise location of the suspected abnormality. The most common form of biopsy involves surgically removing the suspected region. One of the less invasive forms of biopsy, stereotactic fine needle aspiration biopsy, aspirates a small amount of cells for cytologic analysis. The advantages of this technique are that it is minimally invasive, is accurate to less than 2 mm in lesion localization, has sensitivity greater than 90%, and is less expensive than surgical biopsies. But since small (22 gauge) needles are used, cytology on the small amount of material removed is not easy. Far more accurate is large-core needle biopsy (using stereotactic positioning or ultrasound guidance), another alternative to surgical biopsy. Core biopsies remove a 1 mm.times.17 mm core of tissue (if a 14 gauge needle is used) for standard histological examination. However, benign histological diagnoses are difficult to make. In fact, for both fine needle aspiration biopsy and core biopsy, the techniques are only useful when they return a positive result for malignancy. In all other cases, the suspicious lesion must undergo incisional or excisional surgical biopsy. False negatives in analyzing an x-ray mammogram occur when benign tumors or xe2x80x9cnormalxe2x80x9d breast tissue with radiological densities similar to cancer completely or partially mask a malignant tumor which does not exhibit primary or secondary mammographic signs of carcinema. False positives are also problematic because they reduce the acceptability of mammography by the general public and lead to unnecessary biopsies.xe2x80x9d
U.S. Pat. No. 5,800,350 for an apparatus for tissue type recognition by Coppleson et al, patented Sep. 1, 1998, provides the following background information, xe2x80x9cThe early detection of tissues displaying pre-cancer or cancer modifications is important for successful medical treatment. Presently-used detection techniques suffer from inaccuracy and are subject to operator error as well as being time-consuming. A good example of this is the Pap smear for cervical cancer. X-ray diagnosis, which can also be used for detecting advanced cancer modifications, can lead to detrimental exposure to radiation. A positive result produced by a Pap smear test is generally followed by a visual examination using a colposcope which provides a magnified view of the cervix. Suspect regions of the cervix are evaluated by a skilled practitioner who then makes a subjective judgement of the tissue observed. There are many tissue types in the cervix, some of which display analogous appearances, including visual and textural characteristics, that make clinical diagnosis very difficult and subject to error. Similar subjective assessments play a major role in the detection and treatment of other locations of neoplastic pre-activity and activity, for example skin melanoma. Methods and devices have been developed in an attempt to use measurements of physical characteristics of the tissue for distinguishing cancerous tissue from non-cancerous tissue. Electrical measurements of the skin or tissue have been used. Such electrical measurements on their own do not provide the information needed for an effective diagnosis.xe2x80x9d
U.S. Pat. No. 6,026,323 for a tissue diagnostic system by Skladnev et al, patented Feb. 15, 2000, provides the following background information, xe2x80x9cThe identification of tissue type based upon responses to incident light and/or electrical stimulation is well known. This has led to diagnostic techniques and apparatus for identifying tissue types such as cancerous or pre-cancerous. Existing techniques for identifying cancers run the gamut from microscopic examination of tissue smears by trained cell pathologists, to the study of the fluorescence, electrical and other physical properties of tissues. Much research has been devoted to the identification and comparison of optical and electrical characteristics of healthy and damaged tissue in the hope that it could lead to new diagnostic techniques.xe2x80x9d
U.S. Pat. No. 6,109,270 for a multimodality instrument for tissue characterization by Robert W. Mah and Russell J. Andrews, patented Aug. 29, 2000 provides the following background information, xe2x80x9cExisting medical instruments provide general diagnoses for the detection of tissue interface such as normal tissue, cancer tumor, etc. However, such detection has been limited clinically to tactile feedback, temperature monitoring, and the use of a miniature ultrasound probe for tissue differentiation during surgical operations. Stereotactic computed tomography (CT) scanners, magnetic resonance imaging (MRI) devices, and similar other instruments provide guided brain biopsy and preoperative scans for use in neurosurgical surgeries. These scans allow samples of brain tissue to be obtained with some degree of accuracy. However, existing devices provide diagnostic data of limited use, particularly in neurosurgery, where the needle used in the standard stereotactic CT or MRI guided brain biopsy provides no information about the tissue being sampled. The tissue sampled depends entirely upon the accuracy with which the localization provided by the preoperative CT or MRI scan is translated to the intracranial biopsy site. Any movement of the brain or the localization device (e.g., either a frame placed on the patient""s head, or fiducials/anatomical landmarks which are in turn related to the preoperative scan) results in an error in biopsy localization. Also, no information about the tissue being traversed by the needle (e.g., a blood vessel) is provided. Hemorrhage due to the biopsy needle severing a blood vessel within the brain is the most devastating complication of stereotactic CT or MRI guided brain biopsy.xe2x80x9d
Features and advantages of the present invention will become apparent from the following description. Applicants are providing this description, which includes drawings and examples of specific embodiments, to give a broad representation of the invention. Various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this description and by practice of the invention. The scope of the invention is not intended to be limited to the particular forms disclosed and the invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.
The present invention provides an optical probe for tissue identification. The probe includes an elongated body. Optical fibers are located within the elongated body for transmitting light to and from the tissue. Light fluctuation protection is associated with the optical fibers. In one embodiment the light fluctuation protection associated with the optical fibers includes a reflective coating on the optical fibers to reduce stray light. In another embodiment the light fluctuation protection associated with the optical fibers includes a filler with very high absorption located within the elongated body between the optical fibers.
The invention is susceptible to modifications and alternative forms. Specific embodiments are shown by way of example. It is to be understood that the invention is not limited to the particular forms disclosed. The invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.